Semiconductor device and manufacturing method thereof

Abstract

It is an object to provide a display device of which image display can be favorably recognized. Another object is to provide a manufacturing method of the display device with high productivity. Over a substrate, a pixel electrode that reflects incident light through a liquid crystal layer, a light-transmitting pixel electrode, and a structure whose side surface is covered with a reflective layer and which is positioned to overlap with the light-transmitting pixel electrode are provided. The structure is formed over a light-transmitting etching-stop layer, and the etching-stop layer remains below the structure as a light-transmitting layer.

What is claimed is: 
     
       1. A semiconductor device comprising:
 a structure including a side surface, a bottom surface and a top surface; 
 a first pixel electrode; 
 a second pixel electrode over the structure; 
 a first transistor electrically connected to the first pixel electrode; 
 a second transistor electrically connected to the second pixel electrode; 
 a liquid crystal over the structure, the first pixel electrode, the second pixel electrode, the first transistor, and the second transistor; and 
 a reflective layer covering the side surface of the structure, 
 wherein an area of the bottom surface of the structure is larger than an area of the top surface of the structure. 
 
     
     
       2. The semiconductor device according to  claim 1 , wherein each of the first transistor and the second transistor include an oxide semiconductor. 
     
     
       3. The semiconductor device according to  claim 1 , wherein the reflective layer includes aluminum or silver. 
     
     
       4. The semiconductor device according to  claim 1 , wherein the first pixel electrode is configured to reflect an incident light. 
     
     
       5. The semiconductor device according to  claim 1 , wherein the bottom surface of the structure is in contact with an oxide semiconductor. 
     
     
       6. The semiconductor device according to  claim 5 , wherein a refractive index of the structure is higher than a refractive index of the oxide semiconductor. 
     
     
       7. The semiconductor device according to  claim 1 , wherein the second pixel electrode comprises a light-transmitting electrode. 
     
     
       8. A semiconductor device comprising a plurality of pixels, each of the plurality of pixels comprising:
 a structure including a side surface, a bottom surface and a top surface; 
 a first pixel electrode; 
 a second pixel electrode over the structure; 
 a first transistor electrically connected to the first pixel electrode; 
 a second transistor electrically connected to the second pixel electrode; and 
 a reflective layer covering the side surface of the structure, 
 wherein an area of the bottom surface of the structure is larger than an area of the top surface of the structure. 
 
     
     
       9. The semiconductor device according to  claim 8 , wherein each of the first transistor and the second transistor include an oxide semiconductor. 
     
     
       10. The semiconductor device according to  claim 8 , wherein the reflective layer includes aluminum or silver. 
     
     
       11. The semiconductor device according to  claim 8 , wherein the first pixel electrode is configured to reflect an incident light. 
     
     
       12. The semiconductor device according to  claim 8 , wherein the second pixel electrode comprises a light-transmitting electrode. 
     
     
       13. The semiconductor device according to  claim 8 , wherein the bottom surface of the structure is in contact with an oxide semiconductor. 
     
     
       14. The semiconductor device according to  claim 13 , wherein a refractive index of the structure is higher than a refractive index of the oxide semiconductor. 
     
     
       15. A semiconductor device comprising:
 a structure including a side surface, a bottom surface and a top surface; 
 a transparent pixel electrode over the structure; 
 a reflective pixel electrode; 
 a first transistor electrically connected to the transparent pixel electrode; 
 a second transistor electrically connected to the reflective pixel electrode; and 
 a reflective layer covering the side surface of the structure, 
 wherein an area of the bottom surface of the structure is larger than an area of the top surface of the structure. 
 
     
     
       16. The semiconductor device according to  claim 15 , wherein each of the first transistor and the second transistor include an oxide semiconductor. 
     
     
       17. The semiconductor device according to  claim 15 , wherein the reflective layer includes aluminum or silver. 
     
     
       18. The semiconductor device according to  claim 15 , wherein the bottom surface of the structure is in contact with an oxide semiconductor. 
     
     
       19. The semiconductor device according to  claim 18 , wherein a refractive index of the structure is higher than a refractive index of the oxide semiconductor.